The effects of dsRNases on RNA interference efficiency in insects and future research directions

RNA interference (RNAi), a gene silencing mechanism mediated by double-stranded RNA (dsRNA), is critical for insect gene function research and sustainable pest control. However, RNAi efficacy varies drastically across insect orders, with dsRNA stability, tightly linked to the action of double-stranded ribonucleases (dsRNases), as a key determinant. This review focuses on three representative insect orders characterized by differences in RNAi efficiency: Lepidoptera (low RNAi efficiency), Coleoptera (robust environmental RNAi), and Orthoptera (efficient systemic RNAi), systematically exploring the characteristics of dsRNases in each order and their impact on RNAi efficiency. Specifically, in Lepidoptera, dsRNases show tissue-specific expression patterns, and the rapid degradation of exogenous dsRNA significantly weakens the RNAi effect. In Coleoptera, midgut dsRNase compromises feeding-triggered RNAi and its knockdown enhances RNAi potency. In Orthoptera, pH-dependent dsRNase activity can cause divergent RNAi efficiency between injection and oral delivery. The review also outlines key dsRNA stabilization strategies, including genetic suppression of dsRNase via RNAi or CRISPR/Cas9, and physical protection using nanoparticle carriers to enhance dsRNA stability and cellular uptake, which show cross-species application potential. These findings lay a foundation for refining gene silencing protocols and improving eco-friendly pest control. Future work should focus on elucidating the molecular mechanism of dsRNA degradation by dsRNases, developing targeted inhibitors and delivery systems, and validating strategies of inhibiting dsRNases by assessing their field performance across diverse pests.